These machines work when operators pump them with gases or liquids and the inflation results in specific shape changes and desired movements. To impart more versatility to the devices, Stephen L. Craig and colleagues wanted to take advantage of the molecular changes that occur when a robot curls or twists.
The researchers incorporated colour-changing compounds into the materials that make up the robot that are activated when stretched. This feature could help a robot camouflage itself when it moves. And, because the colour change is most intense where the strain on the material is highest, it can also indicate where it's vulnerable to breaking.
The researchers note that other compounds could also be added to release drug molecules, make a robot glow or repair the material when it ruptures.
